Practicum for Exam #1

Question 1

Which leads provide an inferior view of the heart?

Answer 1

Lead II; Lead III; aVF.

Question 2

Which leads provide an anterior view of the heart?

Answer 2

V2; V3; V4.

Question 3

Which leads provide a left lateral view of the heart?

Answer 3

Lead I; aVL; V5; and V6.

Question 4

Which leads provide a view of the right ventricle?

Answer 4

V1 and aVR.

Question 5

What are the criteria for Normal Sinus Rhythm (NSR)?

Answer 5

(1) Normal HR (60-100); (2) regular rhythm; (3) normal PR-interval; (4) normal QT-interval.

Question 6

How do you assess P-waves?

Answer 6

Ensure a P-wave precedes each QRS complex (may not be visible on every beat, but consistent throughout); assess amplitude, shape, and duration.

Question 7

What does a normal P-wave look like?

Answer 7

Rounded; not tall, thin, or abnormally wide.

Question 8

What does a tall, thin P-wave represent?

Answer 8

Right atrial enlargement.

Question 9

What does a wide, often notched, P-wave represent?

Answer 9

Left atrial enlargement.

Question 10

What does a P-wave that is both tall AND wide represent?

Answer 10

Biatrial enlargement

Question 11

How long is a normal PR-interval?

Answer 11

Less than 1 large box.

Question 12

What does a prolonged PR-interval indicate?

Answer 12

First-degree heart block.

Question 13

What does the Q-wave represent?

Answer 13

Septal depolarization.

Question 14

What does a pathologic Q-wave look like?

Answer 14

The depth is at least 1/3 the height of the R-wave; drops straight down (no upward divet before deflection)

Question 15

What does a pathologic Q-wave represent?

Answer 15

Past myocardial infarction.

Question 16

What is R-wave progression?

Answer 16

A normal pattern of progressively increasing R-wave amplitude moving right to left in the precordial leads.

Question 17

What does poor R-wave progression indicate?

Answer 17

Right-sided hypertrophy.

Question 18

What does a normal QRS complex look like?

Answer 18

Narrow is normal; should be less than three small boxes.

Question 19

What does a wide QRS complex indicate?

Answer 19

The impulse is not being generated in the SA node (ectopic pacemaker), or is taking an aberrant pathway through the ventricles.

Question 20

What does the ST segment look like?

Answer 20

Should line up flat with the PQ segment, and the segment following the T-wave.

Question 21

What does ST elevation indicate?

Answer 21

Active myocardial infarction.

Question 22

What does ST depression indicate?

Answer 22

Active cardiac ischemia.

Question 23

What is the characteristic shape of a STEMI?

Answer 23

“Tombstone appearance”; the presence of an up-slope (concave) ST segment is not STEMI, this is caused by J-point elevation.

Question 24

What does a flattened or inverted T-wave represent?

Answer 24

This is a non-specific finding.

Question 25

What is the normal duration for a QT-interval?

Answer 25

The T-wave should fall before the halfway point between two consecutive R-waves.

Question 26

What does a prolonged QT-interval indicate?

Answer 26

Idiopathic; or can be caused by medications. These patients are at an increased risk of developing a ventricular arrhythmia.

Question 27

Describe the pacemaker potential for the different cells of the heart:

Answer 27

SA node (60-100); AV node (40-60); ventricles (20-40).

Question 28

Describe the time axis on an EKG strip:

Answer 28

1 small square (0.04s); 1 large square (0.2s); 5 large squares (1s).

Question 29

What is the easiest way to calculate heart rate from an EKG?

Answer 29

Divide 300 by the number of large squares between QRS complexes.

Question 30

What is another way to calculate heart rate from an EKG?

Answer 30

300-150-100-75-60-50 method.

Question 31

How can you tell if a person has right axis deviation?

Answer 31

QRS is negative in Lead I and positive in aVF.

Question 32

What does right axis deviation represent?

Answer 32

Right ventricular hypertrophy.

Question 33

How can you tell if a person has left axis deviation?

Answer 33

QRS is positive in Lead I and negative in aVF.

Question 34

What does left axis deviation represent?

Answer 34

Left ventricular hypertrophy.

Question 35

How can you tell if a person has extreme right axis deviation?

Answer 35

QRS is negative in BOTH Lead I and aVF.

Question 36

What is the most important criteria for diagnosing left ventricular hypertrophy?

Answer 36

The R-wave amplitude in V5 or V6 plus the S-wave amplitude in V1 or V2 is greater than 7 boxes.

Question 37

What does a down-sloping ST segment indicate?

Answer 37

Secondary repolarization abnormality; commonly seen with hypertrophy.